doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Ithaca Flues 16 gauge Grade 3 pressure question

I recently bought a grade 3 Flues made in 1912 and had a question about shell pressures. It has Krupp barrels, but the barrel walls at the chambers seems fairly thin. I don't have a wall thickness gauge, but there's not much meat on those bones. With 28" barrels it weighs 6 lbs. even. It doesn't look like there has been any honing done on the bores or chambers. It action is very tight. I have some Gamebore 2 1/2" 16 shells, but I'm hesitating using any in in this one. Does anyone have an opinion on suitable pressures for the Ithacas?

What is the pressure of the shells you have?

If I remember correctly from a thread on this board the Gamebores are 8,200 psi in 16 gauge. I have some components, but mostly just Remington wads. I'm waiting on some SG16 wads to come in so I can load lower pressure.

Probably best to stay on the side of caution. Prior to the Great War, the boys along Fall Creek were making some pretty light 16-gauge guns --



A No. 3 Flues of that era is a pretty nice gun. Pics?

If I was worried about wall thickness I would measure them or have a competetent gunsmith measure them. I posted the unaltered chamber end wall thicknesses of several smallbore barrel sets in this thread:

http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=240566#Post240566

It includes a Flues with Krupp steel barrels that I shoot low pressure reloads in.

If Gamebore is not publishing the pressure of their loads then I don't think they are under any obligation to make sure their shells meet anything but SAAMI pressures. Do they publish them?

I would be comfortable shooting 8200 psi loads in my Krupp steel Flues.



Best,

Mike

Thanks for the info, guys. That is an interesting link, Mike. The chamber wall just forward of the rim recess is 0.162" if that means anything. I really do need to get a wall thickness gauge. I don't have any pictures of this one yet. Nice looking engraving on these early Ithacas though. This one has ejectors so I guess it is a 3E.

Bob Ithaca Flues models were more prone, if not notorious, for cracks in the frame thought to be caused primarily by a design flaw due to a lack of sufficient radius at the joint of barrel flats and the standing breech. The sure way to reduce the risk of cracking the frame is using reduced recoil loads. I would select a 1 ounce load producing 1,170 fps or less or a 7/8th ounce load producing 1250 fps or less. Both loads produce a recoil of 15 foot pounds of recoil energy. Remember there is no direct correlation between chamber pressure and recoil.

Thanks for the reply, Twicebarrel. It would only be used for ruffed grouse or sharptails, so a 7/8 oz load at less that 1250 would be fine. I'm a bit surprised that a light shotgun like this is choked so tightly. Both barrels are stamped with a 4 which in another thread should mean full chokes. Is that common in the Ithaca 16 gauges?

I am also amazed at how many old light guns are tightly choked. Garwood wrote that he believed the plastic wad and shot cup had the effect of one degree of choke tightening. That is a 3/4 shot like a 4/4. Of course these guns were designed to shoot paper cartridges with fiber wads and a overshot card.

Best,

Mike